This invention concerns an interconnecting wear device for implementing the low-pressure casting of molded parts made of metal alloys having a high melting point, such as cast-iron, steel, and superalloys, from a melting furnace or pouring ladle into a sand mold, under the propulsive pressure of a gas and by feeding the mold upwardly from the bottom.
French Patent No. 1,187,724 discloses a tube for the pressurized feed of a mold. The top end of the feed tube is attached to a housing. A mixture fills the empty spaces between the housing and the feed tube, thus forming a joint. A collar is mounted on the top part of the housing. The interconnecting device produced according to this Patent does not prevent or reduce the thermal and mechanical stresses affecting the feed tube. In fact, this device, although positioned on the top section, encloses the tube, which rises to a height equal to that of the device. The cooling of the metal begins at the top. The tube thus undergoes thermal shocks which are more violent than those affecting the device, which is separated from the metal by the thickness of the tube.
Furthermore, during cooling the metal solidifies in the feed tube. This solidified metal is removed mechanically, a procedure engendering mechanical shocks in the tube
The combination of thermal and mechanical shocks leads to the rapid wear of the feed tube which, during a first phase, destroys its surface quality, thereby producing leaks, and, during a second phase, requires that the tube be replaced. This repair is costly and requires a lot of time. In fact, the furnace must be shut off and then drained, thus tying up said melting furnace or pouring ladle and mold.